Traffic signal and lighting system



Nov. 8, 1938. L, J. JENNINGS TRAFFIC SIGNAL AND LIGHTING SYSTEM Filed May 5, 1936 2 Sheets-Sheet 1 o. u e 3 p I W V!- mw w T/ R flm a "/5 w A m my 5 1938' J. JENNINGS TRAFFIC SIGNAL AND LIGHTING SYSTEM Filed May 5, 1936 2 Sheets-Sheet 2 Clock W 1. ATTORNEY.

Patented Nov. 8, 1938 UNITED ,STATES PATENT OFFICE scum.

My invention relates to a combined trafllc signal and street lighting system, wherein both the street lights and traihc signals may be operated from a single series circuit.

I In many street lighting systems the street lamps, whether of incandescent or are character, are connected in a series circuit fed by a variable voltage transformer which is regulated so as to deliver through the series lighting circuit a con- 1' stant amperage. My present invention makes it possible to operate traiilc signals from such series lighting circuits, thereby avoiding the necessity of running separate electric circuits for trafllc signals. It is an object of my invention to provide a trafllc signal, such as a flashing lamp signal, which includes a signal circuit including a transformer connected in series in the constant current series street lighting circuit the signal circuit including a flashing lamp and a conduct I ance connected in series in the signal circuit,

there being a motor driven switch means energized by the signal circuit and operable to alternately energize the lamp and the conductance, the energization' of the conductance during the B6 intervals in which the lamp is de-energired preventing an increase 01' voltage to the motor of the switch means during the time the lamp is deenergized.

It is an object of the invention to provide a 80 traflic signal having an electric current consuming member, such, for example, as a lamp or a motor, fed from the secondary oi! a transformer which has its primary in series with the series street lighting circuit, there being means for as keeping a substantially constant load on the secondary circuit of the transformer. 1

It is a further object of the invention to provide a signal and lighting system of the above described character, wherein the signal may be 40 operated regardless of whether the lamps are illuminated or not. and it is a further object oi the invention to provide means whereby control may be accomplished by imposing electrical impulses on the series circuit. For example, high 45 frequency or radio impulses, or direct current impulses, may be directed along the conductor forming the series circuit to accomplish various types of control of electrically operated devices by the series circuit.

It is a further obiect oi the inventtion to provide a lig ting and tramc sign ystemhaving simple means for eliminating the street lighting lamps from the series circuit without interfering with the operation of the traflic signal devices.

i 55 Further objects and advantages of the invention will be made evident throughout the following part of the specification.

Referring to the drawings, which are for illustrative purposes only.

Fig. 1 is an electrical diagram showing a simple form of my invention.

Fig. 2 is an electrical diagram showing a manner oi superimposing electrical control impulses on the series lighting circuit.

Fig. 3 is an electrical diagram showing a form 01' the invention wherein means separate from the series circuit are employed to control the turning on and oi! oi the street lamps without interfering with the operation of the inside signals.

In the simple form oi my invention shown in Fig. l, a series lighting circuit is shown including a conductor ll leading from one side of the secondary I2 01 a variable automatic regulating transformer I! having a primary winding l4. Asshown at ii, the opposite side of the secondary II is grounded. In the conductor H a relatively large number of lamps II are connected in series, and the end ll of the conductor is grounded as indicated at II. The voltage output or the secondary I2 is automatically regulated to preserve a given amperage flow through the secondary circuit which includes the lamps IS. The current flow in the secondary circuit may be established at a value such as "1% amperes.

- Into the series lighting circuit represented by the conductor I I, I connect any desired number of electric current consuming devices it which in the present disclosure are in the form of traflic signals of the character used at boulevard stops, such signals ordinarily employing a flashing lamp to attract the attention of motorists to the fact that a stop should be made. The devices I! each include a transformer 2! having a primary winding 3! connected in series with the conductor H, and a secondary winding 23 connected by conductors II and 25 with a small timing or flashin motor 2' which drives a cam 21. This cam 2'! is adapted to periodically reciprocate a lever member ll constituting the movable part oi a switch. This member II is connected by means of a wire I! with the conductor ti and is adapted to alternately engage contacts ii and 32. When the member 28 is in contact with the contact 3 l elec tric current from the secondary winding 23 will flow through a conductor 33, a signal lamp ll, and a conductor 3| which is connected to the conductor ll, so that at this time the lamp 3| will be illuminated. Revolution of the cam 21 results in movement of the member 2| away from the contact 3| into engagement with the contact 32 so that the lamp 34 will be tie-energized but a circuit will be completed through a. current consuming member or conductance 36 which is connected between the contact 32 and the wire 85. The conductance 36 has the same resistance as the lamp 34, with the result that when the lamp N is de-energized, it is replaced in the circuit by a current consuming member 36 of the same value; therefore, there will be no change in the load placed on the transformer 2| and in turn on the series lamp circuit represented by the conductor l I. It will be understood that even though there are a large number of lamps ll being continuously turned on and oil, there will not be a fluctuation in the current flow through the street lighting lamps l6 owing to the fact that whenever a lamp 34 is deenergized, it is replaced in the electrical system by an equivalent current consuming element 38.

In the form of the invention shown in Fig. l. the lamps M can be illuminated only when the circuit represented by the conductor ii is energized. Accordingly, the lamps 34 can be used only during the time the street lamps ii are illuminated. In the form of the invention shown in Fig. 3, I show a means whereby Signals operated from a series street lighting circuit may be continuously operated through the use of means for eliminating the street lighting lamps from the series circuit as desired. Here. I show the voltage regulating transformer it connected so that its secondary I! will feed a conductor 31 having a plurality of electric lamps ll connected in series therewith. Operative from the series circuit. I show a signal device 30 and a signal device ll. Each of these devices 3! and ll employs a transformer 2| having a primary winding 22 connected in series with the conductor 31, and each device .may have a by-pass or bridging switch 43 connected across the ends of the primary winding 22.

The signal device 39 shown in Fig. 3 has a timing motor 44 connected by means of conductors l5 and 46 with the secondary 22 of a transformer II. This timing motor 44 drives cams l1 and 48 for operating switch means ll and ill. By means of a conductor I2, "stop" and "go" lamps U3 and B4 are connected to the wire l0. From the wire ll a conductor 5! extends to the switch member I which. under operation of the cam H, is adapted to alternately engla'econtacts i6 and 51 which are respectively connected to the lamps i3 and BI. As the switch member 40 is operated, the lamps II and I4 are alternately brought into circuit with the secondary 22 of the transformer 2 I. with the result that the load on the circuit occasioned by these lamps is substantially constant. Between the stop" and "go" lamps. I show a wait lamp ll, one side 01 which is connected to the conductor 52 and the other side of which is connected to a switch contact 5a. The cam 48 is adapted to move the switch member SI alternately back and forth, in a desired timed relatfcfln, between the contact I! and a contact 6| which is connected to a conductance 82 having the same resistance as the lamp 88. This conductance I2 is connected through a wire '8 with the conductor 52, and the switch member I is connected to the conductor .5, the result being that as the cam moves the switch member backand forth, the "wait" lamp 58 will be thrown into circuit, and then when the "wait" lamp is disconnected from the circuit by movement of the switch member Ill toward the contact II, the current consuming member '2 will be substituted for the lamp 58.

In the signal device ll 1 show a motor '4 adapted to operate "stop" and go" signal arms I! and 88. One terminal of the motor 64 is connected througha conductor 61 with the secondary 23 of a transformer 2|, and the other terminal of the motor 84 is connected through a conductor 68 with a switch contact 69 placed on one side of a reciprocating switch member II which is connected through a conductor 12 with the secondary 23. On the opposite side of the member II from the contact 69 is a switch contact I3 which is connected through a conductor 14 with a current consuming element 15 which is in turn connected through a conductor 16 with the wire 61. A timer Tl may be employed to reciprocate the switch member Ii so that it will alternately engage the contacts ll and II, thereby ilrst energizing the motor 84 through a prescribed cycle, and then de-energizlng the motor 84 and substantially instantaneously connecting the current consuming element It, which may be a resistance winding, into the secondary circuit of the transformer 2| in place of the motor, thereby k pin a substantially constant load on the electric supply system so that noticeable fluctuations will not be produced therein.

that the lamps 28 may be turned oil and on as desired, I provide by-pass switches 80 bridged across the lamps II as shown. When these switches 80 are closed, the lamps 38 will be by-passed and accordingly will not be illuminated by the how of electric current through the series circuit. As shown in the upper part of Fig. 3. automatic means, such as a clock 82, for example, may be employed to close a by-pass switch ll; or, as shown in the lower part of Fig. 3, a

conductor 83 forming part of a series control circuit may be extended parallel to the conductor 81 with solenoids I connected in series with the conductor 83. when a switch 88 is closed so as to connect a current supply source. such as a generator ll, with the conductor ll. current will flow through the solenoids N and then to groundat 81, and the current flow will, return through round to the ground connection 88 of the generator 86. When the solenoids N are thus energized, the switches Ill associated with the control c uit, represented by the conductor II will be cl and the associated lamps 38 will not be illuminated, but current from the transformer II of Fig. 3 will continue to flow through the conductor 31 for energization oi the electrical elements of the signals 82 and II.

For the purpose oi exercising control in lighting and signal systems of the character hereinbefore described, electrical energy of different characteristics may be imposed in the series street lighting and signal circuit upon the alternating current flow impressed in the line by a transformer such as the transformer ii. In Fig. 2 I show a transformer ll of automatic voltage regulating type adapted to automatically maintain a prescribed current value in a series conductor ll. one end of which is connected to the secondary winding l2 of the transformer II and the other end oi which is grounded as indicated at 8i. This conductor ll is connected in series with a plurality of streets lamps l2 and in series with a number of signal devices ll of the generalcharacter hereinbeiore described. By-pass contacts M bridged across each of the lamps l2, and when illumination of the lamps 92 is not desired, a knife or plug contact II is disposed between and in connection with the contacts 94. This knife contact 99 is connected to a yoke 99 having downwardly extending lugs 91 and 99 adapted to be alternately engaged by an armature 99 of a polarized relay I99 connected in series with the conductor 99 as indicated. As long as there is merely an alternating current flow through the conductor 99 and through the winding I92 of each polarized relay I99, the armature 99 will remain in a centralized position. A direct current flow through the conductor 99, either while the alternating current is turned oil, or superimposed on the alternating current, will cause the armature 99 to move either to the left or to the right depending upon the polarity of the direct current flow. Accordingly, should it be desired to move the knife blades 95 leftwardly into open position relative to the contacts 94, a direct current flow is passed through the conductor 99 and the windings I92 in series therewith, of proper polarity to cause the movement of the arma tures 99 in leftward direction whereby the extremities thereof will engage the lugs 91 of the yokes 98, moving the yokes 99 in leftward direction. A reversal of the polarity of the direct current flow will cause the armatures 99 to move rightwardly, engaging the lugs 99 and moving I the yokes 96 rightwardly so as to force the knife blades 95 back into engagement with the contacts 94. For this purpose I have shown a direct current generator I95 connected through a polarity reversing switch I96 with a conductor I91 connected to ground and with a reactance or choke coil I98 connected to a switch I99 which is in turn connected through a conductor II9 with the conductor 99 of the series lighting circuit. I have also shown a switch H2 in the conductor 99 between the secondary I2 and the point where the conductor "9 engages the conductor 99, so that the alternating current supply to the lighting and signal circuit may be turned oil before the closing of the switch I99 to send a momentary direct current impulse out through the conductor 99. Likewise, I have shown a switch H9 for the primary II of the transformer I9. Should the switch I99 be closed through the conductor 99, the reactance I99 wili prevent any substantial alternating current flow through the generator I95.

In the upper part of Fig. 2 I show a flashing type of signal IIE operated from the series street lighting system. A transformer 2|, having a primary 22 connected in series with the conductor 99, has i v secondary 29 connected to a conductor Illywhich extends to a lamp I II. From the lamp 'III a conductor "9 extends to the end II9 of a heater element Ill, and is also connected to a switch contact I22. The remaining end I29 0!. the heating element is connected through a conductor I24 with the secondary 29. The conductor I 29 is also connected to a thermostatic element I29 carrying a contact I29 adapted to engagethe contact I22. when the contacts I22 and 129 are separated, current will flow through the, heater I2l and the p I" with the result that the lamp I" will furnish a very dim light. The heat generated by the heater I2I will cause the thermostatic element I29 to move the contact I29 into engagement with the contact I22 so that the current flow through the secondary circuit will bypass the heater, causing the lamp III to burn at full capacity. The subsequent cooling of the thermostat element I moves the contact I29 out of engagement with the contact I22, so that there will again be a reduced flow of current through the heater Hi. The intermittent opening and closing of the switch formed by the contacts I22 and I29 results in a continuous flashing of the lamp III.

I claim as my invention:

1. In combination in a street lighting and signaling system: a constant current series lighting circuit; a transformer having the primary thereof connected in series in said lighting circuit; a load circuit connected in circuit with the secondary of said transformer; an electrically energizable element connected in series in said load circuit; a conductance connected in series in said load circuit; a motor energized by potential induced in said load circuit; and switch means operated by said motor and arranged to intermittently close said load circuit through said electrically energizable element to intermittently operate the same and to close said load circuit through said conductance during the intervals when said lamp is de-energiaed.

2. In combination in a street lighting and signaling system: a constant current series lighting circuit; a load circuit including a lamp inductively connected to said series circuit and including a motor energized by potential induced in said load circuit: switch means operated by said motor and intermittently energizing said lamp to flash the same; and a conductance having substantially the same current-consuming characteristic as said lead lamp connected in series with said lamp in said load circuit, said switch means operated by said motor and closing said load circuit through said conductance during the intervals when said lamp is de-energized to maintain the load on said series lighting circuit substantially constant. I

3. In combination in a street lighting and signaling system: a constant current lighting circult; a transformer having the primary thereof connected in series in said lighting circuit; a load circuit having the secondary of said transformer connected in series therewith; an electrically en- .ergizable element connected in series in said load gized by potential induced in'said load circuit;

and switch means including a contact and a cam operated by said motor for moving said contact to intermittently close said load circuit through saidelectrically energizable element and said honductance, whereby the load on said constant curre'nt circuitis maintained substantially constant.

LEO J. JENNINGS.

- CERTIFICATE OF CORRBCTIOI. Patent No. 2 ,136,l9l. November 8, 1958.

V 1.20 J. .nmmms.

It is hereby centii'ied that error appears in the printed specification of 'the above nnmbered patent requiring correction as follows: Page 1, first column, line 50, for 'inventtion" read invention; page}, second column, line 1 1, clam 2, strike out the word "10m",- and that the said Letters Patent shouldberead with this correction therein that the samemay conform to the recon! of the case in the Patent Office.

signed and sealed this 27th day or December, A. D. 1938.

Henry Van Arsdal e (Seal) ating Commissioner 6r Patents. 

